Question

21

Answer 1

12

Step-by-step explanation:

Quotient rule,

$a {}^{n} \div a {}^{m} = a {}^{n - m}$

Do this,

a^(n-3)=a^9

Since the exponents have to be the same, this turned into a simple one step equation:

n-3=9

+3 +3

**n = 12, so the final answer is 12.